London , England -LRB- CNN -RRB- -- Lockerbie bomber Abdelbeset al-Megrahi is `` a very sick man , '' but there is no way to tell how long he will live , according to the father of one of the people who died in the 1988 bombing of Pan Am Flight 103 .

Jim Swire , whose daughter Flora died in the terror attack , saw al-Megrahi a week ago in Libya , he said Tuesday .

He also criticized U.S. senators who tried to hold hearings this summer into questions surrounding the release of al-Megrahi .

He said he had written to them to say it was more important to let Scottish legal proceedings run their course , since a review commission had found possible miscarriages of justice in the case .

`` They did n't want to know about that , '' he said of the senators , saying they had not replied to his letter .

The Scottish government released al-Megrahi from prison just over a year ago on the grounds that he had cancer and was not likely to live more than three more months .

Swire , who does not believe that al-Megrahi is guilty , defended the decision .

`` At three months , just over half -LSB- of people with his cancer -RSB- would be dead , '' Swire said .

But after three months , mortality rates level off , and there is no way to predict how long cancer sufferers will live , said Swire , a retired general practicioner .

`` He can walk a few steps , '' Swire said of al-Megrahi .

He did not ask al-Megrahi or his doctors about the Libyan 's medical condition out of respect for his privacy , he said .

But he said the fullness of his face suggested that he was on steroids to slow the cancer .

Al-Megrahi was appealing his conviction when he was freed on compassionate grounds in August 2009 and then dropped the appeal .

Swire thinks al-Megrahi feels guilty about having withdrawn his appeal , since it leaves him with no way to clear his name or for those -- like Swire -- who think he is innocent to have the case reviewed .

But al-Megrahi 's death could change the legal playing field , Swire speculated .

`` If he were to die , the the situation would change , '' and Swire might be able to get the case reopened , he said .

He believes that al-Megrahi `` would see to it that we would be provided with all the information his defense team has assembled , '' he said , adding that the Libyan had not explicitly told him that .

Swire is in the minority among victims ' families in thinking al-Megrahi is innocent .

American officials blasted al-Megrahi 's release at the time and on the first anniversary .

`` As we have expressed repeatedly to Scottish authorities , we maintain that al-Megrahi should serve out the entirety of his sentence in prison in Scotland , '' Secretary of State Hillary Clinton said in a written statement .

President Barack Obama 's assistant on homeland security and counterterrorism , John Brennan , called the release `` unfortunate and inappropriate . ''

Democratic Sens. Robert Menendez and Frank Lautenberg noted that al-Megrahi was only given three months to live when he was released but is still alive .

Menendez noted that on August 20 , 2009 , al-Megrahi stepped off a plane into the arms of a cheering throng in Libya .

`` A mass murderer tasted freedom , experiencing joy , '' Menendez said . `` It was a scene that made the stomach turn ... that made old wounds fresh again in the hearts of those whose family members died at the hands of that man . ''

Lautenberg said , `` It is the families of those victims who deserve compassion , not this terrorist . ''

`` Al-Megrahi ... is very much free , living in the lap of luxury by all accounts , '' Menendez said .

The case has outraged many on both sides of the Atlantic and led U.S. senators to demand answers from Scotland about the details of his release .

Al-Megrahi is the only person convicted in the bombing of Pan Am Flight 103 , which exploded over Lockerbie in December 1988 , killing 259 people on the plane and 11 on the ground .

Most of the dead were Americans . The flight had been heading to New York from Frankfurt , Germany , via London , England , when it blew up .

A special Scottish court in the Netherlands convicted al-Megrahi in 2001 .

CNN 's Melissa Gray contributed to this report .

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Jim Swire , whose daughter died in the bombing of Pan Am 103 , saw bomber last week

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Swire does not believe that Abdelbeset al-Megrahi is guilty

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Al-Megrahi was freed last year on the grounds that he was likely to live only a few months

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270 people died in the bombing of Pan Am Flight 103 over Scotland in 1988